The present invention is related to envelopes for mailing documents and, especially, to envelopes having windows wherein the documents indicate address information that is seen through the windows and wherein the documents are not the same size as the envelope. In such envelopes there is a need to position the documents such that the address may be easily read through the envelope window and such that the document does not shift within the envelope to prevent reading of the address through the window.
Envelope manufacture has become a very specialized field in that envelopes are designed for hundreds of different purposes and each design requires different characteristics and has different limitations. In order to save time and printing costs, windowed envelopes are often utilized. The windowed envelope allows a portion of the contents of the envelope to be seen through an envelope window. In this manner the documents in the envelope can include the receiver's address, if it is properly positioned in the window, and allow the mail service to then deliver the envelope to the addressee.
For various reasons, the size requirements for the envelopes do not always match the size and shape of the contents. For example, some postal regulations may require a special sized envelope in order to obtain a particular mailing rate, whereas the contents to be mailed in the envelope may be smaller than the overall size of the envelope.
When, if the size of the contents is smaller than a windowed envelope and the contents contain the address information, then it is possible for the contents to shift within the envelope so as to prevent the mail service from being able to read the address information. Therefore, while it is desirable for the envelope to be of a particular size and shape, it is also desirable for the interior pocket of the envelope to be limited in shape and size so as to maintain the contents in a specific position to ensure the clear viewing of the address information located on the contents through the envelope window.
One method of limiting the size of the envelope pocket is to simply adhere the facing services of the front and back panels of the envelope together in an attempt to produce a false bottom. That is, a bead of adhesive in a strip may be placed in the middle of and near the lower end of the envelope in parallel, but spaced, relationship to the bottom edge of the envelope to try to adhere both the front and back panel together. A bead or strip of adhesive utilized in this fashion is illustrated in Benz U.S. Pat. No. 3,288,351.
Unfortunately, adhesive utilized in the manner described above is not always affective in joining the front and back panel. In particular, when envelopes of this type are constructed, side panels are rotated inwardly and joined to the front and back panels at the same time the back panel rotated to be adjacent to the front panel so as to form a pocket therebetween.
The side panels are typically fairly short and normally do not extend across the entire width of the envelope. Consequently, near the lateral edges of the envelope, the envelope is at least three layers thick (front panel, rear panel and one side panel), whereas typically in the middle of envelopes, the envelope is only two layers thick (the front panel and the rear panel).
During the manufacturing process adhesive is applied and then the envelopes are folded in an envelope folding machine, placed in cartons and held together while the adhesive dries. Because there are only two layers in the middle of the envelope as compared to three layers on the lateral sides of the envelope, there is not a significant amount of pressure placed against the layers in the middle where the two layers occur and the layers may even be spaced apart at this location. Because of this, there is little or no pressure applied to the adhesive during drying and the adhesive often fails to hold the layers together when applied in the region of the two layers. Thus, the creation of a false bottom fails in such cases.
Therefore, it is desirable to have an envelope in accordance with the present invention wherein the adhesive is utilized to form a highly reproducible limited pocket with a false bottom and wherein the adhesive is applied in the region whereat the envelope is three layers thick as opposed to the region where the envelope is two layers thick.